Lab Test: CA 19-9 Level
- Measurement of carbohydrate antigen 19-9 in serum for the evaluation and treatment of malignant disease, such as pancreatic or hepatobiliary cancer.
- Used for evaluation of response to treatment and surveillance.
- Suspected malignant tumor of ampulla of Vater (Note: Levels can correlate with tumor size and can help predict prognosis.)
- Suspected malignant tumor of biliary tract
- Suspected malignant tumor of colon (Note: Elevated level may be associated with colorectal cancer, but currently is not recommended for evaluation, diagnosis, or monitoring of this condition.)
- Suspected malignant tumor of pancreas (Note: Best used as a diagnostic adjunct in the monitoring of disease in patients with pancreatic cancer)
- Increased levels may indicate:
- Pancreatic carcinoma
- Colorectal cancer
- Hepatobiliary carcinoma
- Cirrhosis, gallstones
- Gastric cancer
- Lung cancer
- Inflammatory bowel disease
- Rheumatoid disease
- Collect a venous blood sample.
- The blood may be sent to a central diagnostic laboratory for CA 19-9 determinations. The results may not be available for 7 to 10 days.
- Apply pressure or a pressure dressing to the venipuncture site and observe the site for bleeding.
- Serum is stable at 2 to 8°C for up to 24 hours; for longer periods, freeze serum at -20°C.
- Plasma should be fresh, not frozen or thawed.
- Explain the procedure to the patient.
- Tell the patient that no fasting is required.
CA 19-9 is a carbohydrate cell-surface antigen that exists on the surface of some cancer cells. It is estimated that ~70% of patients with pancreatic carcinoma and 65% of patients with hepatobiliary cancer have elevated levels of CA 19-9. In patients with pancreatic or biliary cancer and who have a good response to surgery, chemotherapy, or radiation therapy, there should be a notable decline in serum levels of CA 19-9 will confirm this response. A rapid rise in levels may be associated with recurrent or progressive tumor growth. Because of its lack of sensitivity and specificity, CA 19-9 is not effective in screening for pancreatobiliary tumors in the general population.
Carcinoembryonic antigen - tumor marker that is elevated in patients with pancreatobiliary cancer.
MESH Terms & Keywords